Cancer is one of the leading causes of death in the United States and is characterized by uncontrolled increases in abnormal or neoplastic cells that form a tumor mass and invade adjacent tissues. Malignant cells spread by way of the blood system, the lymphatic system to lymph nodes, by migration of cancer cells within the fluids of the peritoneal cavity, and to distant sites in a process known as metastasis.
Numerous compounds are known which are useful in the prevention and treatment of various types of cancer. In order to effectively deliver these compounds by intravenous administration, it is generally preferred that the compounds be in solution to avoid or reduce the risk of blood clotting or other adverse effects that could result if the compounds were delivered in particulate form. Unfortunately, many of these compounds have poor solubility in water, the preferred solvent, and must be delivered using solvents which can cause adverse patient reactions that must in turn be prevented or controlled through the administration of other compounds. For example, paclitaxel is a known inhibitor of cell division or mitosis and is widely used in the treatment of ovarian, breast, lung, esophageal, bladder, head and neck cancers. Paclitaxel is a natural product originally purified from the bark of yew trees, but now obtained by semisynthesis from 10-desacetylbaccatin, a precursor purified from yew leaves. Paclitaxel, however, is poorly water soluble and is conventionally solubilized in Cremophor EL, a formulation comprising 50% ethyl alcohol and 50% polyethoxylated castor oil. Cremophor EL is believed to result in histamine release in certain individuals and patients receiving paclitaxel in that delivery method must normally be protected with a histamine H1-receptor antagonist, an H2-receptor antagonist and a corticosteroid to prevent severe hypersensitivity reactions. Other compounds cannot be effectively administered because they are not soluble in any known solvent that can be tolerated by patients in need of cancer prevention or treatment. As a result, these anti-cancer agents are unavailable for use in cancer prevention or treatment using conventional methods of administration.
While anti-cancer compounds are commonly administered by intravenous injection to patients in need of treatment, it is also known to inject cisplatin and carboplatin into the peritoneal cavity. A comparative study of intravenous versus intraperitoneal administration of cisplatin has been published by Alberts, et al. in the New England Journal of Medicine, 335, 1950-1955 (1996). Dedrick, et al., have published a pharmacokinetic rationale for the advantage of intraperitoneal versus intravenous administration of cisplatin in Cancer Treatment Reports, 62, 1-11 (1978). Similarly, intraperitoneal delivery of cisplatin as an infusion is discussed in Principles of Clinical Pharmacology (Atkinson, et al., Academic Press 2001). To date, however, there do not appear to be any published reports of intraperitoneal delivery of suspensions of poorly water-soluble anticancer compounds.